made good his escape from the apartment and had regained a modicum of self-confidence, he undoubtedly blackmailed his homicidal confrère. His death was merely another manifestation of our inconnu's bent for ridding himself of persons who annoyed him. Furthermore, my theory accounts for the chiselled jewel-case, the finger-prints, the unmolested closet, the finding of the gems in the refuse-tin—the person who took them really didn't want them, y' know—and Skeel's silence. It also explains the unbolting and bolting of the side door."
"Yes," sighed Markham. "It seems to clarify everything but the one all-important point—the identity of the murderer."
"Exactly," said Vance. "Let's go to lunch."
Heath, morose and confused, departed for Police Headquarters; and Markham, Vance, and I rode to Delmonico's, where we chose the main dining-room in preference to the grill.
"The case now would seem to centre in Cleaver and Mannix," said Markham, when we had finished our luncheon. "If your theory that the same man killed both Skeel and the Canary is correct, then Lindquist is out of it, for he certainly was in the Episcopal Hospital Saturday night."
"Quite," agreed Vance. "The doctor is unquestionably eliminated. . . . Yes; Cleaver and Mannix—they're the allurin' twins. Don't see any way to go beyond them." He frowned and sipped his coffee. "My original quartet is dwindling, and I don't like it. It narrows the thing down too much—there's no scope for the mind, as it were, in only two choices. What if we should succeed in eliminating Cleaver
